The Justice Department on Monday approved the merger of Ticketmaster Entertainment and Live Nation, in a deal that combines two of the most important companies in the music industry, but required concessions that federal officials said would protect consumers from higher prices on tickets to concerts and other entertainment.

Ticketmaster is the country's largest seller of tickets to concerts, sports games and other live events. Live Nation is another major ticket-seller and runs more than 100 concert venues. Both companies own a variety of affiliated businesses.

The prospect of a joint company raised concerns among politicians, consumer advocates and others in the industry of a monopoly that could significantly accelerate the already-established trend of rising ticket prices.

The Ticketmaster and Live Nation merger was the first major deal to come before the Obama administration's Justice Department. Antitrust chief Christine A. Varney has pledged to reinvigorate enforcement of laws barring anti-competitive practices after years when the Bush administration seldom took action to curb industry consolidation. The case may be viewed as a template for other mergers under review by the Justice Department, in particular cable giant Comcast's acquisition of NBC Universal from General Electric. The settlement requires the approval of the United States District Court in Washington.

Varney said the original Ticketmaster-Live Nation deal "was anti-competitive," adding: "This settlement will preserve competition in primary ticketing and maintain incentives to innovate and discount."

Under the terms of the approval, Ticketmaster must license its ticketing software to competitors, sell a subsidiary and agree to several other measures that federal officials said would give other companies a fair shot to compete against the new firm.

Consumer representatives took a skeptical view of the settlement.

"The DOJ has asked consumers, independent promoters, ticket brokers, artists, and venue owners to take a very large leap of faith -- that the conditions imposed on the merger will improve competition and ultimately lead to greater choice and lower prices," said Sally Greenberg, executive director of the National Consumers League, which had written to regulators in opposition to the deal. "We remain concerned that these two companies, with a history of anti-consumer behavior, will abide only by the letter, and not the spirit of the settlement agreement."

Seventeen states and Canada endorsed the Justice Department's settlement.

Executives of the newly combined company, called Live Nation Entertainment, praised the settlement. "We are close to finalizing the creation of a new company that will seek to transform the way artists distribute their content and fans can access that content," said Michael Rapino, who will head the new company.